Lajcak made the remarks in Baku at the press-conference following the meeting with Azerbaijani Foreign Minister Elmar Mammadyarov, Trend reports on March 5.
He said that Slovakia chairing the OSCE supports the settlement of this conflict.
"The OSCE Minsk Group is the only recognized format in the negotiations and any changes must be coordinated," Lajcak added.
The conflict between the two South Caucasus countries began in 1988 when Armenia made territorial claims against Azerbaijan. As a result of the ensuing war, in 1992 Armenian armed forces occupied 20 percent of Azerbaijan, including the Nagorno-Karabakh region and seven surrounding districts.
The 1994 ceasefire agreement was followed by peace negotiations. Armenia has not yet implemented four UN Security Council resolutions on withdrawal of its armed forces from the Nagorno-Karabakh and the surrounding districts.